Absorbent Article Elastic Member Positioning and Guiding Mechanism

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Solution Overview

Problem

Conventional manufacturing methods for absorbent articles, such as disposable diapers, face issues with positional shifts and twisted assemblies due to uneven contraction of elastic members, particularly at the junctions of foreside and backside regions, leading to product quality failures.

Innovation Solution

An apparatus and method that employs a swinging mechanism to dispose elastic members in a wavy shape on a continuum, with a guiding mechanism to maintain the shape and a cutting mechanism to secure the elastic members, ensuring coincident tangential directions at deviation and arrival points to prevent positional shifts during the manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an elastic member is disposed in a wavy shape on a continuum by a swinging mechanism to fit the leg-line portion, then the fitting to the wearer is improved, but positional shifts and twisted assemblies occur due to uneven contraction of the elastic member

Engineering Contradiction:
Improvefitting to leg-line portionVSAvoidpositional accuracy of continuum
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

A guiding member is introduced as an intermediary device to convey both the continuum and elastic member together along its outer periphery. This mediator ensures that both materials move in coordination, preventing the elastic member from contracting unevenly and causing positional shifts or twisted assemblies during the manufacturing process

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the elastic member is disposed to deviate from the widthwise end portion of the continuum to cover the entire leg-line region, then the fitting is further improved, but the elastic member must be cut and removed in downstream steps

Engineering Contradiction:
Improvecoverage of leg-line regionVSAvoidnumber of manufacturing steps
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The excess portion of the elastic member that deviates from the continuum is extracted and removed by a cutting mechanism positioned downstream. This allows the elastic member to initially cover the entire leg-line region for optimal fitting, while the unnecessary portions are cleanly removed in a dedicated cutting step

Inventive Principle:
Principle #2Taking out (Extraction)

3Stability of the object's composition

If the continuum is conveyed through a guiding mechanism with swivel rotation, then the elastic member shape is maintained, but tangential direction misalignment may cause positional shifts at deviation and arrival points

Engineering Contradiction:
Improveshape maintenance of elastic memberVSAvoidalignment at joining points
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The tangential directions at the deviation point and arrival point of the continuum are pre-aligned to be coincident with each other before the continuum enters the guiding mechanism. This preliminary alignment ensures that when the continuum deviates from and returns to the guiding member, there is no misalignment or positional shift at the joining points

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively restrains positional shifts and contraction forces, ensuring accurate assembly and improved product quality by maintaining the elastic member's shape and adherence to the continuum, thereby enhancing the fitting and comfort of absorbent articles.

Implementation Method 1

a guiding member that conveys the elastic member and the continuum to be taken along an outer periphery of the guiding member

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

a contraction due to a stress of the elastic member hardly occurs

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2856991B1Absorbent article manufacturing device and absorbent article manufacturing method
Publication Date: 2017.07.05 UNI CHARM CORP
  • EP2856991B1 patent drawingFigure 1
  • EP2856991B1 patent drawingFigure 2
  • EP2856991B1 patent drawingFigure 3

AI summary

An apparatus for manufacturing absorbent articles includes :a swinging mechanism that feeds an elastic member while swinging the elastic member along a cross direction crossing a conveyance direction of a sheet-shaped continuum constituting an absorbent article, and that disposes a part of the elastic member on the continuum; a guiding member that conveys the elastic member; a cutting mechanism that cuts the elastic member; a joining mechanism that conveys the elastic member and the continuum that are supplied from the guiding mechanism to be taken along an outer periphery of the joining mechanism; and a sheet supply mechanism that supplies a sheet member onto an end portion in the cross direction of the continuum. A tangential direction of a deviation point at which the continuum is spaced from the guiding mechanism and a tangential direction of an arrival point at which the continuum reaches the joining mechanism are coincident with each other.